1. Field of the Invention
The invention relates to a multimedia system, and more particularly, to a multimedia system capable of adjusting its own settings based on an environmental condition.
2. Description of the Prior Art
In recent years, with the advance of various electronic products, both commercial and household multimedia systems are becoming more popular. The most important hardware in a multimedia system is generally the display apparatus for displaying an image. Therefore, how to enhance the quality of the display apparatus and satisfy users' needs on display characteristics are two important considerations for designers.
Taking the brightness of an image for example, in a relatively bright environment, the brightness of the display need be increased so the observer does not feel that the screen is too dark to see the image clearly. On the contrary, in a relatively dark environment, the bright image may be too intense to the observer's eyes to cause discomfort of the observer. Therefore, most display apparatuses provide a setting interface for users to adjust the brightness as desired.
In order to reduce the inconvenience of manually finding or starting the setting interface, some display apparatuses are provided with external brightness sensors. These display apparatuses can adjust the brightness of the backlight modules according to the detected result of the brightness sensors, i.e., the brightness in the environment of the display apparatuses.
However, because the image on the display apparatus is only a part of what the user visually perceives, the sensed result of the aforementioned brightness sensor may not wholly represent the environmental luminance that the user feels. When there is a distance between the user and the display apparatus, the sensed result of the brightness sensor could be much different from what the user actually feels. For example, when the user sits on a sofa three meters away from the TV screen, the user could be influenced by nearby light sources to feel that the image of the display apparatus, in the relatively darker place, appears to be darker than it in fact is. Thus, the user is still obligated to manually adjust the brightness setting of the display apparatus, such that the brightness sensor fails to fulfill its intended function.
It is to be noted that, the color of an object changes along with the color of the light illuminated thereon. Human eyes can automatically correct the changes resulted by such light, but manufactured sensors lack the correction function. Therefore, images taken or recoded under different lights have different color temperatures. A large number of image processing systems are designed with the function of white balance for correcting the color errors caused by the light to allow the digital image to appear more true to what human eyes observe.
As known by those skilled in the art, determining the color temperature of an image is generally the first step in a white balance procedure. In addition to considering the color temperature of the image, some display apparatuses are also provided with external color temperature detecting devices. The display apparatus is capable of performing the white balance adjustment based on the detected result of the color temperature sensor, i.e., the color temperature in the environment of the display apparatus, so as provide congruity between the image and objects nearby the display apparatus. However, compared to the aforesaid brightness sensor, the color temperature sensor has the same shortcoming of being incapable of truly reflecting visual perception and needs of the user.